Love him or loathe him, Kevin Pietersen's return from a knee injury in time to face Australia in the Ashes series will have left England supporters breathing a sigh of relief.

Kevin Pietersen has given England a timely boost by returning in time for the Ashes

The controversial South Africa-born middle-order batsman, who divides opinion off the field with as much ease has he destroys opposition bowlers on it, is the England player the Australians fear the most.

"There's only certain players that you can fear and they're the Pietersens, the (Brian) Laras and Viv Richards," former Australian batsman Damien Martyn said.

"In Pietersen you can sense he can win a game in a session - he's dangerous."

Pietersen, 33, has played little cricket since returning early from the tour of New Zealand in March due to injury but the right-hander scored a century for Surrey last month in his first innings of the season.

"He is very important to our side. He is a superstar with the bat who can dominate and intimidate opposition," England coach Andy Flower said.

"He is a big physical presence and a big personality, and those people influence sporting contests."

Pietersen has a history of falling out with colleagues and his antics have led to accusations that he is not a team player.

But when he dazzles the crowd and opposition with his flamboyant strokeplay and performances such as the swashbuckling 158 at the Oval in 2005 that helped secure the Ashes and a career-best 227 in Adelaide in 2010, much can be forgiven.

However, the spontaneity Pietersen displays in his batting has had a tendency to show itself as rashness off the field.

He fell out with his captain at his first county side, Nottinghamshire, and threatened legal action in a bid to leave the club.

In 2008, Pietersen was appointed England captain but quit five months later following the breakdown of his relationship with coach Peter Moores, who was sacked.

The advent of social media has only served to bring examples of Pietersen's impetuous nature to the notice of a wider audience.

In 2010, he was fined for a foul-mouthed outburst on Twitter after being left out of the England squad for the one-day and Twenty20 series against Pakistan and was punished again last year for using the social media site to criticise a pundit.

His most recent transgression occurred last year when he was dropped for the final Test against South Africa at Lord's after sending provocative texts to opposing players.

Pietersen underwent a process of reintegration and committed to playing for England in all three forms of the game before being allowed back into the national fold.

He made his comeback in India in November and in characteristic fashion reminded England what they had been missing by blasting 186 in his second Test back.

"When Kevin's got a point to prove he usually proves it with the bat," his former England team mate Andrew Flintoff told the BBC last year.

Aside from his many external conflicts, Pietersen appears to battling an internal one, considering himself an introvert in stark contrast to the brash persona he presents in public.

"I'm very much an introverted person. I like my own company, my own family. I don't really go out much," Pietersen said in a BBC interview,

"I think the confidence has grown from what I've achieved on the cricket field but I'm not as confident as anybody thinks."

Born in Natal in 1980 to a South African father and English mother, Pietersen began his cricketing career as an off-spinner.

He first came to England's notice in 1999 when he made 61 not out, batting at nine, and took four wickets for KwaZulu-Natal against Nasser Hussain's side in a tour match.

Frustrated at South Africa's racial quota system, Pietersen left for England and ended up at Nottinghamshire in 2001 where he averaged almost 60 with the bat in his first season.

He became eligible for England in 2004 and made his debut in a one-day series in Zimbabwe, announcing his international arrival with a man-of-the-match 77 in his second game before going on to make three centuries against the country of his birth in 2005.

Pietersen is England's top century maker across the three forms of the game with 31.

In 94 Tests he has scored 7,499 runs at an average of 49.01. Captain and opener Alastair Cook is the only active England player to have scored more (7,524).

"If Kevin Pietersen's not available for the Ashes I think Australia will win," Australian great Shane Warne told Sky Sports news in May.

"I think he's that big a player for the England team. Everyone feeds off him. He's such a destructive player."